Thread cutter for looms



INVENTOR CLIFFORD DARWIN C. DARWIN THREAD CUTTER FOR LOOMS Filed Aug. 22, 1951 June 16, 1953 ATTORNEY Patented June 16, 1 95? THREAD CUTTER FOR LooMs Clifiord Darwin, Paxton, Mass, assignor to Crompton & Knowles Loom Works, Worcester, Mass, a corporation of Massachusetts Application August 22, 1951, Serial No. 243,029

. 9 Claims.

This invention relates to thread cutters for the outgoing thread in bobbin-changing looms, and it is the general object of the invention" to provide an actuator for the movable blade of the cutter operated by the lay but so constructed and mounted that any lateral motion of the actuator incident to its engagement with the lay will not be transmitted to the movable blade.

In certain types of bobbin-changing looms it is desirable to cut the thread of the outgoing bobbin near the thread delivery eye of the shuttle. This result has been accomplished in one known thread cutter in which the movable cutter blade has a depending arm which is struck by the lay as the latter advances on a bobbin-changing beat of the loom. In such cutters, however, the blow of the lay against the arm is likely to twist the movable blade on its pivot sufiiciently so that its cutting edge doesnot move along the edge of the fixed blade, and, as a result, the thread is not out even though it is between, the'blades. This condition is even more likely to exist in those instances where the movable blade arm slides along the lay.

It is an important object of the present inventhe aforesaid actuator lever for angular move.-

ment around the axis or stud on which the movable blade turns.

The thread cutter is ordinarily mounted on some form of carrier which moves rearwardly,

from its normal forward position when a cutting operation is to occur. The present invention contemplates the mounting of the actuator lever on the carrier so it will be moved rearwardly within the range of motion of the advancing lay when the cutter is called upon to. operate. The carrier is shown herein asa lever pivoted 'between its ends on a vertical axis and under control of the bobbin transferrer arm, but certain features of the invention are not limited to the carrier lever.

In order that the invention may be clearly understood reference is made to the accompanying drawings which illustrate byway of example one embodiment of the invention and in which:

Fig. 1 is a plan view of one end of a bobbinchanging loom, parts being in section, having the present invention applied thereto.

Fig. 2 is an enlarged detail side elevation looking in the direction of arrow 2, Fig. 1 showing the thread cutter in cutting position about to cut a thread, parts being in section.

Fig. 3 is a horizontal section on line 3 3,

Fig. 2. a

Fig. 4 is a detail vertical section on line 4-4, Fig. 3.

Fig. 5 is a detail vertical sectionon line 5-5, Fig.2.

Fig. 6 is a detail vertical section on line 6-43, Fi 1.

th lay carrying reed 8. In the present instance the front of the shuttle box is formed by a shuttle binder 9 pivoted to stud ID on the shuttle box and having a horizontal slot I l therein. The shuttle S has a front wall l2 formed with a horizontal slot I 3 which'registers horizontally with slot H when the shuttle is boxed as shown in Fig. 1. h

As shown in Fig. 1 the shuttle carries a bobbin B, the weft supply of which is substantially depleted, The weft thread to be cut, indicated at r T, extends from the bobbin through the shuttle eye l4 along the lay in front of the shuttle, across slots 1 I and I3, then continues to the left and is attached to the cloth 3 at the cloth fell [5. The thread extends across and rests on a mass l6 of deformable material in the top of the lay, and a pneumatic thread remover R is provided to attract the thread T.

The loom frame supports a reserve bobbin magazine having a foot I! secured to the loom frame at 18. Most of the magazine is omitted from the drawings, but the upright 19 therefor, shown in section in Fig. 1, has integral therewith the usual bearing 20 supporting a horizontal stud transferrer arm 23 of the usual bobbin transfer mechanism. A torsion, spring :24 .connected at 3 its right end, Fig. 1, to a collar 25 and at its left end to hub 22 normally holds the transferrer arm up and a finger 25 on arm 23 in rear position.

A support 36 is secured at 3| to stud 2| and has secured thereto a vertical stud 32 in front of the lay and having the lower end thereof formed as a head 33 on which the hub 34 of a carrier 35 rests. A collar 35 angularly adjustable on stud 32 is attached to the upper end of a torsion spring 31, the lower end of which is attached to the carrier lever and normally holds the latter in the position shown in Fig. 1 with the left arm 38 thereof against finger 26.

Arm 4:; of lever 35 extends to the right, Fig. l, and has secured thereto a carrier 4| in front of the lay. The carrier has a stem 42 extend ing forwardly through bearing 43 of arm 35 and held in adjusted back and forth position relative to lever 35 by set screw 44. A pivot 45 shown as a stud in Fig. 3, has a bearing 46, a reduced screw threaded end 41 tapped into the carrier and held fixed thereto by nut 43, and a head 49. The thread cutter mechanism, des ignated generally at C, comprises a blade 55 fixed to the carrier and a second movable or pivoted blade Both blades fit the bearing 46 and a pin 52, driven into the carrier il, fits snugly into a notch 53 in the forward end of blade 55, the right end in Fig. 4, and together with bearing it fixes the blade 59 against angular position around the pivot 45. Pin 52 extends into a larger hole 54 in the forward end of blade 5| and limits angular motion of the provided blade around pivot 45. A torsion spring 55 around bearing 45 normally holds the cutter mechanism C in the open position shown in Fig. 2 with the rear part of the cutting edge 56 of blade 5| above the rear part of the cutting edge 5? of blade 5! to define a thread bight 58. Spring 55 is also under compression and holds the pivoted blade 5| against the'fixed blade 50.

Much of the mechanism thus far described may be similar to thread cutting mechanism shown for instance in patent to Payne, No. 1,881,920 and patent to Turner No. 2,398,264 and is set forth to illustrate one form of carrier for the cutter mechanism controlled by a part such as the transferrer arm of a bobbin-changing loom having a movement on a replenishing beat of the loom. The invention, however, is not limited to the particular carrier or manner of its control already described.

In carrying the present invention into effect an actuator means separate from the pivoted blade 5| is provided for its operation. A shell or sleeve bearing 60 has an out-turned flange 5| fitting into a circumferential notch 62 in head 49 of the pivot stud 45. This notch holds the sleeve 60 concentric with the bearing 66 and the head holds the end of the sleeve adjacent to movable cutter blade 5| against the latter with a light pressure which does not interfere with the rocki'ng of blade 5| on the bearing 45.

An actuator, shown as a lever 55, has a hub 66 rotatable on the sleeve and has a depending operating arm 61 for engagement with the head 63 of a screw 59 secured to and extending forwardly from the main part of the lay, but as contemplated herein forming part of the lay.

Actuator lever 55 has a forwardly extending arm ID on which is a lateral stud 1| fitting into a hole- E2 in the forward part of the cutter blade. Hole 12 is preferably slightly larger than the stud 1| so that the pivoted blade and the actuator lever can have some slight relative angular motion and also to enable the actuator lever to move bodily away from the pivoted blade with out disturbing the latter relative to the fixed blade. The hub 56 is of such length that it is capable of limited sliding movement on sleeve- 65 in a direction toward and from the pivoted blade 5|.

In operation, the parts will be in the position shown in Fig. 1 at the beginning of a cutting operation. The carrier lever is shown in its normal position and latch '53 forming part of the bobbin transfer mechanism has been raised by means not shown into the path of bunter 14 on the advancing lay. The thread cutter mechanism C will be in forward position in front of the lay and will be open to define bight 58 and depending arm 5? of the actuator lever 65 will be in rear position relative to carrier 4|.

As bunter 74 pushes latch '53 forwardly, finger 28 will rock forwardly around stud 2| and spring 3? will rock carrier lever 35 in a counterclockwise direction, Fig. 1 to move the right hand arm thereof and also carrier 4| rearwardly. During this rearward motion arm 6'3 will engage head 68 of screw 63 and rock the actuator lever and cause the latter, acting through stud H, to move the pivoted blade 5i around pivot 35 from the position shown in Fig. 2 to that shown in Fig. 8, thereby efiecting cutting of the thread T. Pin 52 will thereupon stop further turning of blade 5| and lever relative to the carrier 4 after which the carrier lever will swing around stud 32 as the lay continues to advance.

In the past, thread cutters of this general type have had the equivalent of arm ii'l fastened di rectly on blade 5i and any lateral motion imparted'by the lay to such arm, whether caused by impact when the lay struck the arm or by sliding of the latter along the lay, was communicated to the moving blade and twisted it so that its edge would not remain engaged with the edge of the fixed blade. In the present instance, however, such lateral motion of arm 5? will not be communciated to the blade 5| and the latter can perform its proper cutting operation without being disturbed by twisting of lever 65 on sleeve 69 or sliding movement along the latter.

From the foregoing it will be seen that the invention provides a thread cutting mechanism wherein the pivoted blade 5| is moved by an actuator, here shown as lever 55, separate from the blade and capable of lateral motion incident to engagement with the lay without causing twisting or movement of the cutting edge 55 of blade 5| away from blade 5?}. Also, the pivot stud 45 provides the axis for both the blade 5| and the actuator lever 65. The latter is slidable to a limited extent along sleeve 60, which is held between blade 5| and head 49 of stud 4-5. Furthermore, the operative connection between the actuator lever and the blade 5!, shown here as stud 1| extending into blade 5!, is loose and prevents the aforesaid twisting of the actuator lever from being passed onto the pivoted blade. Also, spring 55, which need not necessarily be of the torsion type shown, not only returns the blade 5| to normal open position, but also acts through stud H to return the actuator lever to its normal position after a cutting operation.

Having now particularly described and ascertained the nature of the invention and in what manner the same is to be performed, what is claimed is:

1. In thread cutting mechanism for a bobbinchanging loom having a lay and wherein a thread to be cut extends along th lay, a carrier normally in forward position in front of the lay, a

thread cutter blade fixed with respect to the carand move said operating arm into the path of the advancing lay, the lay thereupon engaging said operating arm and causing pivoted movement of the actuator lever, and operative connections between the actuator lever and said second cutter blade effective due to said pivotal movement of the actuator lever to move said second blade to closed position to cutsaid thread, said operative connections being loose to permit lateral movement of the actuator lever relative to thesecond cutter blade incident to engagement of the operatingv arm by the lay.

2. The thread cutting mechanism set forth in claim 1 wherein a spring tends normally to hold said second blade in the open position thereof and is efiective through said operative connections to return the actuator lever to normal position subsequent to a thread cutting operation.

3. The thread cutting mechanism set forth in claim 2 wherein a sleeve surrounds said pivot andthe actuator lever is rockably mounted on said sleeve.

4. The thread cutting mechanism set forth in claim 3 wherein said actuator lever has a hub slidable along said sleeve to permit lateral motion of the actuator lever which may result from engagement of said operating arm with the lay.

5. The thread cutting mechanism set forth'in claim 3 wherein the pivot is a stud having a head and the sleeveis located around and concentric with the stud between said head and the second cutter blade.

6. The thread cutting mechanism set forth in claim 1 wherein the operative connections include a stud on the actuator lever fitting loosely into a hole in the second cutter blade.

7. In thread cutting mechanism for a loom having a lay which moves forwardly during a weft replenishing operation and wherein a thread to be cut extends along the lay, a carrier, a carrier lever supporting the carrier pivoted in front of the lay and operative incident to a weft replenishing operation to swing to move said carrier from a normal front position rearwardly toward the lay, a normally open thread cutter mounted on said carrier, an actuator lever pivoted with respect to said carrier having an arm which moves into the path of the lay when said carrier moves rearwardly, and operative connections between said thread cutter and said actuator lever efiective when said arm is engaged by the advancing lay to close the thread cutter to out said thread, said arm sliding along the lay incident to closing of the thread cutter and said operative connections being loose to permit lateral movement of the actuator lever relative to the thread cutter incident to sliding of the arm along the lay.

8. In thread cutting mechanism for a loom having a lay which moves forwardly during a weft replenishing operation and wherein a thread to be cut extends along the lay, a carrier, a carrier lever supporting the carrier pivoted in front of the layand operative incident to a weft replenishing operation to swing to move said carrier from a normal front position rearwardly toward the lay, a pivot on said carrier, a cutter blade fixed relatively to said carrier, a second cutter blade mounted for angular movement on said pivot, said fixed and second blades normally being in open position, an actuator lever supported by said carrier for angular motion around said pivot and having an arm which moves into the path of the advancing lay when said carrier moves rearwardly, the lay engaging said arm to rock said actuator lever around said pivot, and operative connections between said second blade and said actuator lever effective to move said second blade to close the cutter to cut the thread when the actuator lever is rocked around said pivot by the advancing lay, said carrier leverbeing swung pivotally incident to the cutting operation and causing said arm to' slide along the lay, said operative connections being so constructed as to be ineffective to transmit to said second blade any lateral motion of the actuator lever incident to sliding of the arm along the lay.

9. In a weft thread cutting mechanism for a loom having bobbin transferrer mechanism operated by a lay and wherein a thread to be cut extends along the lay, a lever pivoted intermediate its ends about a vertical axis having one end thereof engaging the transferrer mechanism and effective upon operation of the latter to move the other end thereof toward the lay, a cutter blade fixed with respect to said other end of the lever, a pivot stud supported by said other end of the lever, a second cutter blade pivoted on the stud, an actuator lever mounted to pivot around said pivot stud operatively connected to said second blade and having an arm for engagement with the lay, said other end of the leverwhen moving toward the lay moving said arm into the path of the lay and the latter during forward movement thereof engaging said arm and rocking said actuator lever about said pivot stud to move said second blade to cut the thread.',

CLIFFORD DARWIN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,687,464 Reece Oct. 9, 1928 1,881,920 Payne l Oct. 11, 1932 2,398,264 Turner Apr. 9, 1946 

